Endoscopic cutting forceps with jaw clamp lever latching mechanism

ABSTRACT

A lever latching system comprising: a housing; a lever having a latch pin fixedly mounted to the lever, the lever being movably mounted to the housing so that the latch pin moves in an arc; and a latch plate movably mounted to the housing for linear movement with respect to the housing, the latch plate comprising a labyrinth for receiving the latch pin.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No. 17/176,478, filed Feb. 16, 2021, which is a Continuation of U.S. patent application Ser. No. 16/410,510 filed May 13, 2019 and issued on Mar. 9, 2021 as U.S. Pat. No. 10,942,537, which is a Continuation of U.S. patent application Ser. No. 15/817,996 filed Nov. 11, 2020 and issued on Jun. 11, 2019 as U.S. Pat. No. 10,317,927 which is a Continuation of U.S. patent application Ser. No. 14/706,146, filed on May 7, 2015 and issued on Dec. 26, 2017 as U.S. Pat. No. 9,851,741, which claims benefit of U.S. Provisional Patent Application Ser. No. 61/994,179, filed May 16, 2014 the contents of which are hereby incorporated herein by reference in their entireties.

FIELD OF THE INVENTION

This invention relates to surgical apparatus and methods in general, and more particularly to endoscopic cutting forceps and jaw clamp lever latching mechanisms for use with the same and/or for use with other lever-actuated devices.

BACKGROUND OF THE INVENTION

Endoscopic cutting forceps are well known in the art. In general, endoscopic cutting forceps comprise a pair of jaws disposed at the distal end of a shaft, a blade cutter configured to reciprocate in the space between the jaws (and hence cut tissue disposed between the pair of jaws), and a handle disposed at the proximal end of the shaft for carrying a lever for actuating the pair of jaws and a trigger for actuating the blade cutter. In some constructions, the endoscopic cutting forceps allow the pair of jaws and the blade cutter to be rotated as a unit about the axis of the shaft, and/or the endoscopic cutting forceps allow the pair of jaws to be electrically energized so as to provide electrocautery function to the endoscopic cutting forceps.

In general, it can be convenient to provide a latching mechanism for the lever which actuates the jaws, whereby to allow the jaws to be temporarily locked (or clamped) in a closed position about tissue, e.g., while the blade cutter is actuated to cut the tissue disposed between the clamped jaws.

Unfortunately, current latching mechanisms for endoscopic cutting forceps tend to be mechanically complex and hence difficult and/or expensive to manufacture.

Thus there is a need for a new and improved latching mechanism for an endoscopic cutting forceps wherein the latching mechanism is mechanically simple and hence easy and inexpensive to manufacture.

There is also a need for a new and improved latching mechanism for the actuating levers of other surgical instruments and/or other lever-actuated devices wherein the latching mechanism is mechanically simple and hence easy and inexpensive to manufacture.

SUMMARY OF THE INVENTION

The present invention provides a new and improved latching mechanism for an endoscopic cutting forceps wherein the latching mechanism is mechanically simple and hence easy and inexpensive to manufacture.

The present invention also provides a new and improved latching mechanism for the actuating levers of other surgical instruments and/or other lever-actuated devices wherein the latching mechanism is mechanically simple and hence easy and inexpensive to manufacture.

In one form of the present invention, there is provided a lever latching system comprising:

-   -   a housing;     -   a lever having a latch pin fixedly mounted to said lever, said         lever being movably mounted to said housing so that said latch         pin moves in an arc; and     -   a latch plate movably mounted to said housing for linear         movement with respect to said housing, said latch plate         comprising a labyrinth for receiving said latch pin.

In another form of the present invention, there is provided a lever latching system comprising:

-   -   a housing;     -   a lever pivotally mounted to said housing at a pivot point, and         a latch pin fixedly mounted to said lever at a location offset         from said pivot point; and     -   a latch plate movably mounted to said housing for linear         movement with respect to said housing, said latch plate         comprising a labyrinth for receiving said latch pin.

In another form of the present invention, there is provided a latching system comprising:

-   -   a first unit;     -   a second unit comprising a latch pin, said second unit being         movably mounted to said first unit so that said latch pin moves         in a prescribed motion;     -   a selector plate movably mounted to said first unit; and     -   a latch plate comprising a labyrinth for selectively receiving         said latch pin, said latch plate being movably mounted to said         selector plate;     -   wherein said latch plate moves linearly relative to said         selector plate.

In another form of the present invention, there is provided a latching system comprising:

-   -   a first member;     -   a second member comprising a latch pin, said second member being         movably mounted to said first member so that said latch pin         moves in a prescribed motion;     -   a selector plate movably mounted to said first member;     -   a latch plate movably mounted to a selector plate and comprising         a labyrinth for selectively receiving said latch pin;     -   a spring secured to said selector plate and engaging said latch         plate for biasing said latch plate with respect to said selector         plate;     -   wherein said selector plate moves said latch plate between an         engaged position wherein said labyrinth intersects said         prescribed motion and a disengaged position wherein said         labyrinth does not intersect said prescribed motion.

In another form of the present invention, there is provided a latching system comprising:

-   -   a first unit;     -   a second unit comprising a latch pin, said second unit being         movably mounted to said first unit so that said latch pin moves         in a prescribed motion;     -   a selector plate movably mounted to said first unit; and     -   a latch plate comprising a labyrinth for selectively receiving         said latch pin, said latch plate being movably mounted to said         selector plate;     -   wherein said latch plate comprises an integral spring for         biasing said latch plate relative to said selector plate.

In another form of the present invention, there is provided a latching system comprising:

-   -   a first component comprising a latching pin movable in a         prescribed motion; and     -   a second component comprising a selector plate that moves a         latch plate having a labyrinth between an engaged position         wherein said labyrinth intersects said prescribed motion and a         disengaged position wherein said labyrinth does not intersect         said prescribed motion, said second component comprising a latch         spring secured to said selector plate for biasing said latch         plate with respect to said selector plate.

In another form of the present invention, there is provided a latching system comprising:

-   -   a first unit;     -   a second unit;     -   said first unit and said second unit being movably mounted         relative to one another;     -   a latch pin fixedly mounted to one of said first unit and said         second unit; and     -   a latch plate movably mounted to the other of said first unit         and said second unit for linear movement with respect to said         other of said first unit and said second unit, said latch plate         comprising a labyrinth for receiving said latch pin.

In another form of the present invention, there is provided a latching system comprising:

-   -   a first unit fixedly mounted to a handpiece;     -   a second unit;     -   said first unit and said second unit being movably mounted         relative to one another;     -   a latch pin fixedly mounted to one of said first unit and said         second unit; and     -   a latch plate movably mounted to the other of said first unit         and said second unit for linear movement with respect to said         other of said first unit and said second unit, said latch plate         comprising a labyrinth for receiving said latch pin.

In another form of the present invention, there is provided a latching system comprising:

-   -   a first unit;     -   a second unit pivotably mounted to the first unit;     -   a latch pin fixedly mounted to one of said first unit and said         second unit; and     -   a latch plate movably mounted to the other of said first unit         and said second unit for linear movement with respect to said         other of said first unit and said second unit, said latch plate         comprising a labyrinth for receiving said latch pin.

In another form of the present invention, there is provided a latching system comprising:

-   -   a first unit;     -   a second unit;     -   said first unit and said second unit being movably mounted         relative to one another;     -   a latch pin fixedly mounted to one of said first unit and said         second unit; and     -   a latch plate movably mounted to the other of said first unit         and said second unit for non-linear and non-pivotal movement         with respect to said other of said first unit and said second         unit, said latch plate comprising a labyrinth for receiving said         latch pin.

In another form of the present invention, there is provided a latching system comprising:

-   -   a first unit;     -   a second unit;     -   said first unit and said second unit being movably mounted         relative to one another;     -   a latch pin fixedly mounted to one of said first unit and said         second unit; and     -   a latch plate movably mounted to the other of said first unit         and said second unit for non-pivotal movement with respect to         said other of said first unit and said second unit, said latch         plate comprising a labyrinth for receiving said latch pin.

In another form of the present invention, there is provided a method for operating a mechanism having a first state and a second state, the method comprising:

-   -   providing a lever latching system comprising:         -   a housing connected to the mechanism to be operated;         -   a lever connected to the mechanism to be operated and             pivotally mounted to said housing at a pivot point, and a             latch pin fixedly mounted to said lever at a location offset             from said pivot point; and         -   a latch plate movably mounted to said housing for linear             movement with respect to said housing, said latch plate             comprising a labyrinth for receiving said latch pin;     -   moving said lever so that said latch pin causes said latch plate         to move with respect to said housing so that said latch pin is         disposed at a latched position within said labyrinth, whereby to         cause the mechanism to transition from its first state to its         second state and maintain the mechanism in its second state; and     -   moving said lever so that said latch pin moves out of latched         position within said labyrinth, whereby to cause the mechanism         to transition from its second state to its first state.

In another form of the present invention, there is provided a method for operating a mechanism having a first state and a second state, the method comprising:

-   -   providing a lever latching system comprising:         -   a housing connected to the mechanism to be operated;         -   a lever connected to the mechanism to be operated and having             a latch pin fixedly mounted to said lever, said lever being             movably mounted to said housing so that said latch pin moves             in an arc; and         -   a latch plate movably mounted to said housing for linear             movement with respect to said housing, said latch plate             comprising a labyrinth for receiving said latch pin;     -   moving said lever so that said latch pin causes said latch plate         to move with respect to said housing so that said latch pin is         disposed at a latched position within said labyrinth, whereby to         cause the mechanism to transition from its first state to its         second state and maintain the mechanism in its second state; and     -   moving said lever so that said latch pin moves out of its         latched position within said labyrinth, whereby to cause the         mechanism to transition from its second state to its first         state.

In another form of the present invention, there is provided a method for operating a mechanism having a state and a second state, the method comprising:

-   -   providing a latching system comprising:         -   a first unit connected to the mechanism to be operated;         -   a second unit connected to the mechanism to be operated and             comprising a latch pin, said second unit being movably             mounted to said first unit so that said latch pin moves in a             prescribed motion;         -   a selector plate movably mounted to said first unit; and         -   a latch plate comprising a labyrinth for selectively             receiving said latch pin, said latch plate being movably             mounted to said selector plate;         -   wherein said latch plate moves linearly relative to said             selector plate;     -   moving said second unit so that said latch pin causes said latch         plate to move with respect to said first unit so that said latch         pin is disposed at a latched position within said labyrinth,         whereby to cause the mechanism to transition from its first         state to its second state and maintain the mechanism in its         second state; and     -   moving said second unit so that said latch pin moves out of its         latched position within said labyrinth, whereby to cause the         mechanism to transition from its second state to its first         state.

In another form of the present invention, there is provided a method for operating a mechanism having a first state and a second state, the method comprising:

-   -   providing a latching system comprising:         -   a first unit connected to the mechanism to be operated;         -   a second unit connected to the mechanism to be operated and             comprising a latch pin, said second unit being movably             mounted to said first unit so that said latch pin moves in a             prescribed motion;         -   a selector plate movably mounted to said first unit; and         -   a latch plate comprising a labyrinth for selectively             receiving said latch pin, said latch plate being movably             mounted to said selector plate;         -   wherein said latch plate comprises an integral spring for             biasing said latch plate relative to said selector plate;     -   moving said second unit so that said latch pin causes said latch         plate to move with respect to said first unit so that said latch         pin is disposed at a latched position within said labyrinth,         whereby to cause the mechanism to transition from its first         state to its second state and maintain the mechanism in its         second state; and     -   moving said second unit so that said latch pin moves out of its         latched position within said labyrinth, whereby to cause the         mechanism to transition from its second state to its first         state.

In another form of the present invention, there is provided a method for operating a mechanism having a first state and a second state, the method comprising:

-   -   providing a latching system comprising:         -   a first member connected to the mechanism to be operated;         -   a second member connected to the mechanism to be operated             and comprising a latch pin, said second member being movably             mounted to said first member so that said latch pin moves in             a prescribed motion;         -   a selector plate movably mounted to said first member;         -   a latch plate movably mounted to a selector plate and             comprising a labyrinth for selectively receiving said latch             pin;         -   a spring secured to said selector plate and engaging said             latch plate for biasing said latch plate with respect to             said selector plate;         -   wherein said selector plate moves said latch plate between             an engaged position wherein said labyrinth intersects said             prescribed motion and a disengaged position wherein said             labyrinth does not intersect said prescribed motion;     -   moving said second member so that said latch pin causes said         latch plate to move with respect to said first member so that         said latch pin is disposed at a latched position within said         labyrinth, whereby to cause the mechanism to transition from its         first state to its second state and maintain the mechanism in         its second state; and     -   moving said second member so that said latch pin moves out of         its latched position within said labyrinth, whereby to cause the         mechanism to transition from its second state to its first         state.

In another form of the present invention, there is provided a method for operating a mechanism having a first state and a second state, the method comprising:

-   -   providing a latching system comprising:         -   a first component connected to the mechanism to be operated             and comprising a latching pin movable in a prescribed             motion; and         -   a second component connected to the mechanism to be operated             and comprising a selector plate that moves a latch plate             having a labyrinth between an engaged position wherein said             labyrinth intersects said prescribed motion and a disengaged             position wherein labyrinth does not intersect said             prescribed motion, said second component comprising a latch             spring secured to said selector plate for biasing said latch             plate with respect to said selector plate;     -   moving said first component so that said latching pin causes         said latch plate to move with respect to said second component         so that said latching pin is disposed at a latched position         within said labyrinth, whereby to cause the mechanism to         transition from its first state to its second state and maintain         the mechanism in its second state; and     -   moving said first component so that said latching pin moves out         of its latched position within said labyrinth, whereby to cause         the mechanism to transition from its second state to its first         state.

In another form of the present invention, there is provided a method for operating a mechanism having a first state and a second state, the method comprising:

-   -   providing a latching system comprising:         -   a first unit connected to the mechanism to be operated;         -   a second unit connected to the mechanism to be operated;         -   said first unit and said second unit being movably mounted             relative to one another;         -   a latch pin fixedly mounted to one of said first unit and             said second unit; and         -   a latch plate movably mounted to the other of said first             unit and said second unit for linear movement with respect             to said other of said first unit and said second unit, said             latch plate comprising a labyrinth for receiving said latch             pin;     -   moving one of said first unit and said second unit so that said         latch pin causes said latch plate to move with respect to the         other of said first unit and said second unit so that said latch         pin is disposed at a latched position within said labyrinth,         whereby to cause the mechanism to transition from its first         state to its second state and maintain the mechanism in its         second state; and     -   moving one of said first unit and said second unit so that said         latch pin moves out of its latched position within said         labyrinth, whereby to cause the mechanism to transition from its         second state to its first state.

In another form of the present invention, there is provided a method for operating a mechanism having a first state and a second state, the method comprising:

-   -   providing a latching system comprising:         -   a first unit connected to the mechanism to be operated and             fixedly mounted to a handpiece;         -   a second unit connected to the mechanism to be operated;         -   said first unit and said second unit being movably mounted             relative to one another;         -   a latch pin fixedly mounted to one of said first unit and             said second unit; and         -   a latch plate movably mounted to the other of said first             unit and said second unit for linear movement with respect             to said other of said first unit and said second unit, said             latch plate comprising a labyrinth for receiving said latch             pin;     -   moving one of said first unit and said second unit so that said         latch pin causes said latch plate to move with respect to the         other of said first unit and said second unit so that said latch         pin is disposed at a latched position within said labyrinth,         whereby to cause the mechanism to transition from its first         state to its second state and maintain the mechanism in its         second state; and     -   moving one of said first unit and said second unit so that said         latch pin moves out of latched position within said labyrinth,         whereby to cause the mechanism to transition from its second         state to its first state.

In another form of the present invention, there is provided a method for operating a mechanism having a first state and a second state, the method comprising:

-   -   providing a latching system comprising:         -   a first unit connected to the mechanism to be operated;         -   a second unit connected to the mechanism to be operated and             pivotably mounted to the first unit;         -   a latch pin fixedly mounted to one of said first unit and             said second unit; and         -   a latch plate movably mounted to the other of said first             unit and said second unit for linear movement with respect             to said other of said first unit and said second unit, said             latch plate comprising a labyrinth for receiving said latch             pin;     -   moving one of said first unit and said second unit so that said         latch pin causes said latch plate to move with respect to the         other of said first unit and said second unit so that said latch         pin is disposed at a latched position within said labyrinth,         whereby to cause the mechanism to transition from its first         state to its second state and maintain the mechanism in its         second state; and     -   moving one of said first unit and said second unit so that said         latch pin moves out of its latched position within said         labyrinth, whereby to cause the mechanism to transition from its         second state to its first state.

In another form of the present invention, there is provided a method for operating a mechanism having a first state and a second state, the method comprising:

-   -   providing a latching system comprising:         -   a first unit connected to the mechanism to be operated;         -   a second unit connected to the mechanism to be operated;         -   said first unit and said second unit being movably mounted             relative to one another;         -   a latch pin fixedly mounted to one of said first unit and             said second unit; and         -   a latch plate movably mounted to the other of said first             unit and said second unit for non-linear and non-pivotal             movement with respect to said other of said first unit and             said second unit, said latch plate comprising a labyrinth             for receiving said latch pin;     -   moving one of said first unit and said second unit so that said         latch pin causes said latch plate to move with respect to the         other of said first unit and said second unit so that said latch         pin is disposed at a latched position within said labyrinth,         whereby to cause the mechanism to transition from its first         state to its second state and maintain the mechanism in its         second state; and     -   moving one of said first unit and said second unit so that said         latch pin moves out of its latched position within said         labyrinth, whereby to cause the mechanism to transition from its         second state to its first state.

In another form of the present invention, there is provided a method for operating a mechanism having a first state and a second state, the method comprising:

-   -   providing a latching system comprising:         -   a first unit connected to the mechanism to be operated;         -   a second unit connected to the mechanism to be operated;         -   said first unit and said second unit being movably mounted             relative to one another;         -   a latch pin fixedly mounted to one of said first unit and             said second unit; and         -   a latch plate movably mounted to the other of said first             unit and said second unit for non-pivotal movement with             respect to said other of said first unit and said second             unit, said latch plate comprising a labyrinth for receiving             said latch pin;     -   moving one of said first unit and said second unit so that said         latch pin causes said latch plate to move with respect to the         other of said first unit and said second unit so that said latch         pin is disposed at a latched position within said labyrinth,         whereby to cause the mechanism to transition from its first         state to its second state and maintain the mechanism in its         second state; and     -   moving one of said first unit and said second unit so that said         latch pin moves out of its latched position within said         labyrinth, whereby to cause the mechanism to transition from its         second state to its first state.

In another form of the present invention, there is provided a latching system comprising:

-   -   a first unit;     -   a second unit comprising a latch pin, said second unit being         movably mounted to said first unit so that said latch pin moves         in a prescribed motion;     -   a selector plate movably mounted to said first unit; and     -   a latch plate comprising a labyrinth for selectively receiving         said latch pin, said latch plate being movably mounted to said         selector plate;     -   wherein said latch plate comprises an integral spring for         biasing said latch plate relative to said first unit.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the preferred embodiments of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts, and further wherein:

FIGS. 1-26 are schematic views showing a novel endoscopic cutting forceps formed in accordance with the present invention, wherein the novel endoscopic cutting forceps comprise a novel jaw clamp lever latching mechanism formed in accordance with the present invention, with FIGS. 1-16 generally showing the general features of the novel endoscopic cutting forceps and FIGS. 17-26 generally showing the novel jaw clamp lever latching mechanism of the novel endoscopic cutting forceps; and

FIGS. 27-38 are schematic views showing exemplary operation of the novel jam clamp lever latching mechanism of the endoscopic cutting forceps of FIGS. 1-26 .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Looking first at FIGS. 1-4 , there is shown novel endoscopic cutting forceps 5 which comprise one preferred embodiment of the present invention.

The Novel Endoscopic Cutting Forceps in General

Endoscopic cutting forceps 5 generally comprise a pair of jaws 10 disposed at the distal end of a shaft 15, a blade cutter 20 configured to reciprocate in the space between jaws 10 (and hence cut tissue disposed between the pair of jaws), and a handle 25 disposed at the proximal end of shaft 15 for carrying a lever 30 for actuating the pair of jaws 10 and a trigger 35 for actuating blade cutter 20. Endoscopic cutting forceps 5 preferably allow the pair of jaws 10 and blade cutter 20 to be rotated as a unit about the axis of shaft 15 via a knob 40, and endoscopic cutting forceps 5 preferably allow the pair of jaws 10 to be electrically energized via a button 45 so as to provide electrocautery function to endoscopic cutting forceps 5.

More particularly, and looking now at FIGS. 1-9 , jaws 10 are each secured to the distal end 50 of a support rod 55, with support rods 55 and the proximal ends of jaws 10 being disposed within shaft 15. The proximal ends 60 of support rods 55 are secured to a hub 65, which is itself secured to a wall 70 of handle 25. As a result of this construction, jaws 10 are effectively fixed to handle 25. As seen in the figures, jaws 10 are outwardly biased relative to support rods 55, so that the distal ends of jaws 10 naturally diverge from one another. Jaws 10 comprise slots 75 (FIG. 4 ) which receive blade cutter 20.

Shaft 15 is movable relative to handle 25 so as to selectively close down jaws 10. More particularly, shaft 15 is hollow and is disposed coaxially over the proximal ends of jaws 10 and coaxially over support rods 55. The proximal end of shaft 15 is connected to a mount 80 (FIG. 6 ) which is engaged by lever 30 as will hereinafter be discussed. Shaft 15 has a flange 85 intermediate its length. A compression spring 90 is disposed about shaft 15 between a wall 95 of handle 25 and flange 85 of shaft 15 so as to spring-bias shaft 15 in the proximal direction. Another compression spring 100 may be disposed about shaft 15 between flange 85 of shaft 15 and a surface of mount 80 so as to bias mount 80 proximally.

As noted above, lever 30 may be used to actuate jaws 10. More particularly, lever 30 is rotatably pinned at 105 to handle 25 so that when the finger grip 110 of lever 30 is pulled proximally toward palm grip 115 of handle 25, the opposing end 120 of lever 30 is moved distally, whereby to move mount 80 distally and thereby move shaft 15 distally. Such distal movement of shaft 15 forces jaws 10 to close. When finger grip 110 of lever 30 is released, compression spring 90 returns shaft 15 proximally, whereby to cause jaws 10 to open. Note that blade cutter 20 is received in slots 75 of jaws 10 when jaws 10 are in their open position and blade cutter 20 is also received in slots 75 of jaws 10 when jaws 10 are in their closed position.

Looking now at FIGS. 1-8, 10 and 11 , blade cutter 20 is disposed at the distal end 125 of a drive rod 130, with the proximal end of blade cutter 20 and drive rod 130 being disposed within shaft 15. The proximal end of drive rod 130 is secured to a hub 135.

Trigger 35 actuates blade cutter 20. More particularly, trigger 35 is rotatably pinned at 140 to handle 25 so that when trigger 35 is pulled proximally toward palm grip 115 of handle 25, the opposing end 145 of trigger 35 is moved distally, whereby to move hub 135 distally and thereby move drive rod 130 and blade cutter 20 distally. Note that when jaws 10 are in their closed position and blade cutter 20 is moved distally, blade cutter 20 will ride distally within slots 75 formed in jaws 10.

As noted above, endoscopic cutting forceps 5 preferably allow the pair of jaws 10 and blade cutter 20 to be rotated as a unit about the axis of shaft 15 via a knob 40. To this end, knob 40 drivingly engages mount 80 such that when knob 40 is rotated, mount 80 is also rotated, whereby to rotate hub 65 and thereby rotate support rods 55 and hence jaws 10. Note that inasmuch as blade cutter 20 is received within slots 75 in jaws 10 when jaws 10 are in both their open and closed positions, rotation of jaws 10 will cause blade cutter 20 to rotate in unison with jaws 10.

As also noted above, endoscopic cutting forceps 5 allow the pair of jaws 10 to be electrically energized via a button 45 so as to provide electrocautery function to endoscopic cutting forceps 5. More particularly, and looking now at FIGS. 1-3, 5-9 and 12-16 , in the preferred form of the invention, jaws 10 and support rods 55 are formed out of an electrically conductive material, and button 45 is used to activate a switch which connects a power line 150 to jaws 10. As a result, pressing button 45 electrically energizes jaws 10 so as to provide electrocautery function to endoscopic cutting forceps 5. In this respect it should be appreciated that, where shaft 15 is made out of an electrically conductive material, and/or where drive rod 130 is made out of an electrically conductive material, an insulating member 155 is disposed between shaft 15 and support rods 55 and jaws 10, and between drive rod 130 and support rods 55 and jaws 10, so as to avoid inadvertent short-circuiting of the electrical components of endoscopic cutting forceps 5.

Thus it will be seen that endoscopic cutting forceps 5 generally comprise a pair of jaws 10 disposed at the distal end of a shaft 15, a blade cutter 20 configured to reciprocate in the space between jaws 10 (and hence cut tissue disposed between the pair of jaws 10), and a handle 25 disposed at the proximal end of shaft 15 for carrying a lever 30 for actuating the pair of jaws 10 and a trigger 35 for actuating blade cutter 20. Endoscopic cutting forceps 5 preferably allow the pair of jaws 10 and blade cutter 20 to be rotated as a unit about the axis of shaft 15 via a knob 40, and endoscopic cutting forceps 5 preferably allow the pair of jaws 10 to be electrically energized via a button 45 so as to provide electrocautery function to endoscopic cutting forceps 5.

Novel Latching Mechanism

In accordance with the present invention, there is also provided a novel latching mechanism for the lever which actuates the jaws, whereby to allow the jaws to be temporarily locked (or clamped) in a closed position about tissue while the blade cutter is actuated to cut the tissue disposed between the clamped jaws.

Significantly, the latching mechanism of the present invention is mechanically simple and hence easy and inexpensive to manufacture.

In addition, the latching mechanism of the present invention may also be used for the actuating levers of other surgical instruments and/or other lever-actuated devices wherein the latching mechanism is mechanically simple and hence easy and inexpensive to manufacture.

Looking next at FIGS. 1-3, 5-7, 9-11 and 17-26 , there is shown a latching mechanism 200 which comprises one preferred form of the present invention. Latching mechanism 200 generally comprises a selector plate 205 and a latch plate 210.

Selector plate 205 serves to selectively position latch plate 210 within handle 25. Selector plate 205 is movably mounted to handle 25, and latch plate 210 is mounted to selector plate 205, such that, by adjusting the position of support plate 205 within handle 25, the position of latch plate 210 may also be adjusted within handle 25. In this way selector plate 205 can be used to selectively position latch plate 210 in a “latch operative position” or in a “latch inoperative position” within handle 25, as will hereinafter be discussed.

More particularly, selector plate 205 is slidably mounted to handle 25 of endoscopic cutting forceps 5. A thumb button 215 protrudes through a window 220 formed in handle 25 so that the user can adjustably position selector plate 205 (and hence adjustably position latch plate 210) within handle 25. Detents 225 are formed in selector plate 205 and cooperate with a protrusion 230 formed on handle 25 whereby to allow selector plate 225 to be maintained in a “latch operative position” or in a “latch inoperative position” within handle 25 until urged otherwise by the user.

Latch plate 210 is slidably mounted to selector plate 205. More particularly, latch plate 210 comprises a body 235 having a loop spring 240 extending therefrom (FIG. 24 ). In one preferred form of the invention, loop spring 240 is formed integral with body 235. Loop spring 240 comprises a bore 245 which is mounted on a pin 250 of selector plate 205. Loop spring 240 biases body 235 of latch plate 210 into a given position on selector plate 205, but permits body 235 of latch plate 210 to be slidably moved on selector plate 205 (both towards and away from pin 250 on selector plate 205) against the power of loop spring 240. In one preferred form of the invention, latch plate 210 moves linearly with respect to handle 25 as latch plate 210 moves on selector plate 205. Body 235 of latch plate 210 includes a flange 257 which is slidably mounted on selector plate 205, whereby to stabilize latch plate 210 as it moves on selector plate 205. As a result of this construction, body 235 of latch plate 210 can be urged away from pin 250 of selector plate 205 against the power of loop spring 240, or body 235 of latch plate 210 can be urged toward pin 250 of selector plate 205 against the power of loop spring 240.

A latch element 255 is mounted to body 235 of latch plate 210. In one preferred form of the invention, latch element 255 is formed integral with body 235 of latch plate 210. Latch element 255 comprises a first surface 260, a second surface 265, and a third surface 270 (FIG. 26 ). In one preferred form of the invention, first surface 260 comprises a substantially linear configuration, second surface 265 comprises a concave configuration, and third surface 270 comprises a slightly convex or substantially linear configuration.

First surface 260, second surface 265 and third surface 270 together define a labyrinth (i.e., a non-linear track comprising a leading first surface 260, a concave second surface 265, and a trailing third surface 270, whereby to form a tortuous path with a concavity intermediate its length), and interact with a latch pin 275 (FIG. 26 ) formed on lever 30, so as to provide the desired latching function.

More particularly, when selector plate 205 is appropriately positioned within handle 25 so that the apparatus is configured in the “latch operative position”, and when lever 30 is thereafter pulled toward palm grip 115 of handle 25 (i.e., so as to close jaws 10), latch pin 275 engages first surface 260 of latch element 255 and forces latch plate 210 away from pin 250, against the power of loop spring 240. Latch pin 275 rides along first surface 260 of latch element 255 until latch pin 275 reaches the end of first surface 260, whereupon latch pin 275 moves onto second surface 265 of latch element 255. As soon as latch pin 275 moves onto the concave second surface 265, loop spring 240 pulls body 235 of latch plate 210 back toward pin 250, until latch pin 275 seats at the base of concave second surface 265. At this point, lever 30 will be maintained in this position (i.e., the “latched” position, with jaws 10 clamped) until lever 30 is thereafter pulled again. More particularly, when it is thereafter desired to unclamp jaws 10, lever 30 is pulled again, against the power of loop spring 240, so as to cause latch pin 275 to move out of the base of concave second surface 265 of latch element 255 and further along concave second surface 265. As soon as latch pin 275 clears the end of concave second surface 265 and moves onto third surface 270 of latch element 255, loop spring 240 pulls latch plate 210 back toward pin 250, until latch pin 275 is returned to its original starting position clear of third surface 270. At this point, lever 30 will have been returned to its original starting position, pending a further cycling of endoscopic cutting forceps 5.

It will be appreciated that the latching function just described relies upon the interaction of latch pin 275 with latch element 255. It will also be appreciated that selector plate 205 allows the position of latch plate 210 to be adjusted within handle 25. Thus selector plate 205 provides the ability to render the latching function operative or inoperative by adjusting the position of latch plate 210 (and hence the position of latch element 255) vis-à-vis the position of lever 30 (and hence the orbit of latch pin 275). More particularly, by positioning selector plate 205 so that the position of latch element 255 is outside the orbit of latch pin 275, the selector plate can be used to put the apparatus in a “latch inoperative position”. Conversely, by positioning selector plate 205 so that the position of latch element 255 is within the orbit of latch pin 275, the selector plate can be used to put the apparatus in a “latch operative position”. The user adjusts the position of selector plate 205 using thumb button 215.

Exemplary Operation of the Novel Latching Mechanism of the Endoscopic Cutting Force

FIGS. 27-38 illustrate operation of the endoscopic cutting forceps 5 (note that the specific constructions shown in FIGS. 27-38 may differ slightly from the specific constructions shown in FIGS. 1-26 , however, FIGS. 27-38 depict a common operation of the latching function of the present invention). More particularly, FIGS. 27-35 show endoscopic cutting forceps 5 with selector plate 205 set in the “latch operative position” and with the apparatus cycling through a complete latching/unlatching operation. FIGS. 36-38 show endoscopic cutting forceps 5 with selector plate 205 set in the “latch inoperative position” and with lever 30 cycling through a complete “pull and release” operation.

Alternative Preferred Embodiments

In the preceding description, lever 30 is described as being rotatably pinned to handle 25 at 105. However, it should be appreciated that other connections may also be employed. By way of example but not limitation, lever 30 may be movably mounted to handle 25 by the legs of a so-called “4-bar” mechanism.

It should be appreciated that, if desired, selector plate 205 may move in a direction which is different than the direction of movement of latch plate 210, provided, however, that movement of selector plate 205 moves latch plate 210 into, and out of, the orbit of latch pin 275. By way of example but not limitation, selector plate 205 could move in a direction perpendicular to the direction of movement of latch plate 210, whereby to move latch plate 210 into, and out of, the orbit of latch pin 275.

If desired, latch plate 210 may be movably mounted to selector plate 205 by a variety of means, so as to provide a variety of different movements, e.g., linear movement, pivoting movement, prescribed motion such as by a so-called “4-bar” mechanism, traversing in an arcuate track, etc.

Thus it will be seen that the present invention provides a new and improved latching mechanism for an endoscopic cutting forceps wherein the latching mechanism is mechanically simple and hence easy and inexpensive to manufacture.

It will also be appreciated that the new and improved latching mechanism of the present invention may be used in conjunction with the actuating levers of other surgical instruments and/or other lever-actuated devices, whereby to provide a latching mechanism which is mechanically simple and hence easy and inexpensive to manufacture.

Modifications of the Preferred Embodiments

It will be appreciated that various modifications may be made to the preferred embodiments discussed above without departing from the scope of the present invention.

Thus, for example, the locations of selector plate 205/latch plate 210 and latch pin 275 may be reversed, i.e., selector plate 205 and latch plate 210 may be mounted on lever 30 and latch pin 275 may be mounted on handle 25.

By way of further example but not limitation, selector plate 205 may be omitted, in which case latch plate 210 is slidably mounted directly to handle 25 (or, if the location of latch plate 210 and latch pin 275 are reversed, slidably mounted directly to lever 30). Of course, in this form of the invention, the apparatus is always set in the “latch operative position” and is incapable of being set in the “latch inoperative position”.

It should be understood that many additional changes in the details, materials, steps and arrangements of parts, which have been herein described and illustrated in order to explain the nature of the present invention, may be made by those skilled in the art while still remaining within the principles and scope of the invention. 

What is claimed is:
 1. A latching system comprising: a first member; a second member comprising a latch pin, the second member being movable relative to the first member so that the latch pin is movable in a prescribed motion; a latch plate movably mounted to the first member for linear movement with respect to the first member, the latch plate comprising a labyrinth for selectively receiving the latch pin, the latch plate positionable relative to the second member such that the labyrinth intersects the prescribed motion; and a spring for biasing the latch plate.
 2. The latching system according to claim 1, wherein the first member comprises a housing and the second member comprises a lever.
 3. The latching system according to claim 1, wherein the spring can both extend and compress during movement of the latch plate.
 4. The latching system according to claim 1, wherein the labyrinth comprises a concave surface for seating the latch pin during latching, a first surface for engaging the latch pin prior to seating of the latch pin in the concave surface, and a second surface for engaging the latch pin after the latch pin is unseated from the concave surface.
 5. The latching system according to claim 1, wherein the prescribed motion is arcuate motion.
 6. A latching system comprising: a first member; a second member comprising a latch pin, the second member being movably mounted to the first member so that the latch pin moves in a prescribed motion; a selector plate movably mounted to the first member; and a latch plate movably mounted to the selector plate and comprising a labyrinth for selectively receiving the latch pin; wherein the selector plate is operable to move the latch plate between an engaged position wherein the labyrinth intersects the prescribed motion and a disengaged position wherein the labyrinth does not intersect the prescribed motion.
 7. The latching system according to claim 6, wherein the first member comprises a housing.
 8. The latching system according to claim 7, wherein the second member comprises a lever.
 9. The latching system according to claim 6, wherein the selector plate is movable by actuation of a button, and wherein the button is configured to move the selector plate between a latch operative position and a latch inoperative position.
 10. A latching system comprising: a first member; a second member comprising a latch pin, the second member being movably mounted to the first member so that the latch pin moves in a prescribed motion; a selector plate movably mounted to the first member; a latch plate movably mounted to the selector plate and comprising a labyrinth for selectively receiving the latch pin; and a spring for biasing the latch plate with respect to the selector plate; wherein the selector plate moves the latch plate between an engaged position wherein the labyrinth intersects the prescribed motion and a disengaged position wherein the labyrinth does not intersect the prescribed motion.
 11. The latching system according to claim 10, wherein the prescribed motion is linear motion.
 12. The latching system according to claim 10, wherein the prescribed motion is arcuate motion.
 13. The latching system according to claim 10, wherein the latch plate moves linearly with respect to the selector plate.
 14. The latching system according to claim 10, wherein the labyrinth comprises a concave surface for seating the latch pin during latching, a first surface for engaging the latch pin prior to seating of the latch pin in the concave surface, and a second surface for engaging the latch pin after the latch pin is unseated from the concave surface.
 15. The latching system according to claim 14, wherein the first surface and the second surface are substantially linear.
 16. The latching system according to claim 10, wherein the spring is secured to the selector plate and engages the latch plate.
 17. The latching system according to claim 10, wherein the spring is formed integral with the latch plate.
 18. The latching system according to claim 10, wherein the spring comprises a leaf spring.
 19. The latching system according to claim 10, wherein the spring comprises a loop spring.
 20. The latching system according to claim 10, wherein the spring can both extend and compress during movement of the latch plate. 